2 files changed, 31 insertions, 18 deletions

diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index 8b4acfd92aa3..fef41f5d6e8d 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -6,7 +6,7 @@ ccflags-$(CONFIG_USB_GADGET_DEBUG) := -DDEBUG
 obj-$(CONFIG_USB_GADGET)        += udc-core.o
 obj-$(CONFIG_USB_LIBCOMPOSITE)  += libcomposite.o
 libcomposite-y                  := usbstring.o config.o epautoconf.o
-libcomposite-y                  += composite.o
+libcomposite-y                  += composite.o functions.o
 obj-$(CONFIG_USB_DUMMY_HCD)     += dummy_hcd.o
 obj-$(CONFIG_USB_NET2272)       += net2272.o
 obj-$(CONFIG_USB_NET2280)       += net2280.o
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 9db000013f5d..4aa0e4652228 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -683,6 +683,31 @@ done:
         return result;
 }
 
+int usb_add_config_only(struct usb_composite_dev *cdev,
+                struct usb_configuration *config)
+{
+        struct usb_configuration *c;
+
+        if (!config->bConfigurationValue)
+                return -EINVAL;
+
+        /* Prevent duplicate configuration identifiers */
+        list_for_each_entry(c, &cdev->configs, list) {
+                if (c->bConfigurationValue == config->bConfigurationValue)
+                        return -EBUSY;
+        }
+
+        config->cdev = cdev;
+        list_add_tail(&config->list, &cdev->configs);
+
+        INIT_LIST_HEAD(&config->functions);
+        config->next_interface_id = 0;
+        memset(config->interface, 0, sizeof(config->interface));
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(usb_add_config_only);
+
 /**
  * usb_add_config() - add a configuration to a device.
  * @cdev: wraps the USB gadget
@@ -703,30 +728,18 @@ int usb_add_config(struct usb_composite_dev *cdev,
                 int (*bind)(struct usb_configuration *))
 {
         int                             status = -EINVAL;
-        struct usb_configuration        *c;
+
+        if (!bind)
+                goto done;
 
         DBG(cdev, "adding config #%u '%s'/%p\n",
                         config->bConfigurationValue,
                         config->label, config);
 
-        if (!config->bConfigurationValue || !bind)
+        status = usb_add_config_only(cdev, config);
+        if (status)
                 goto done;
 
-        /* Prevent duplicate configuration identifiers */
-        list_for_each_entry(c, &cdev->configs, list) {
-                if (c->bConfigurationValue == config->bConfigurationValue) {
-                        status = -EBUSY;
-                        goto done;
-                }
-        }
-
-        config->cdev = cdev;
-        list_add_tail(&config->list, &cdev->configs);
-
-        INIT_LIST_HEAD(&config->functions);
-        config->next_interface_id = 0;
-        memset(config->interface, 0, sizeof(config->interface));
-
         status = bind(config);
         if (status < 0) {
                 while (!list_empty(&config->functions)) {